Key Concepts: The somatic neuromuscular junction is the site of communication between motor neurons and skeletal muscle fibres. Specialisations of the neuromuscular junction mean that activity in and release of transmitter from motor neurons produces contraction of skeletal muscle fibres rapidly and reliably.he neuromuscular junction comprises four cell types: the motor neuron, terminal Schwann cell, skeletal muscle fibre and kranocyte, with the motor neuron and muscle fibre separated by a gap called the synaptic cleft.
Causes. Headaches can be triggered by a variety of factors. The most common cause of headaches is prolonged tension or stress. These are called tension headaches or muscle-contraction headaches. Virtually everyone suffers from this at some time. Muscles in your scalp, neck, and face tighten and contract, causing spasms and pain.
Headaches may be triggered by consuming foods such as cheese or chocolate. Depression and anxiety can also cause headaches. Constant headaches can be a sign of a serious problem or a side effect of nutrition supplements or medications.itamin Overdose. Overdosing on vitamins including B vitamins, vitamin D, vitamin A, and vitamin E may cause headaches. Overdosing on vitamins may have other serious symptoms in addition to headaches.